Catheterization and interventional procedures, such as angioplasty or stenting, generally are performed by inserting a hollow needle through a patient's skin and intervening tissue into the vascular system. A guidewire may then be passed through the needle lumen into the patient's blood vessel accessed by the needle. The needle may be removed, and the introducer sheath may be advanced over the guidewire into the vessel e.g. in conjunction with or subsequent to a dilator. A catheter or other device may then be advanced through a lumen of the introducer sheath and over the guidewire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate introducing various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure.
Upon completing the procedure, the devices and introducer sheath may be removed, leaving a puncture site in the vessel wall. External pressure may be applied to the puncture site until clotting and wound sealing occur. This procedure however, may be time consuming and expensive requiring as much as an hour of a physician or assistant's time. It is also uncomfortable for the patient and requires that the patient remain immobilized in the operating room, catheter lab, or holding area. In addition a risk of a hematoma exists from bleeding before hemostasis occurs.
Various apparatus have been suggested for percutaneously sealing a vascular puncture by introducer sheath into a puncture site. When deployed, the plug seals the vessel and provides hemostasis. Such plugs, however, may be difficult to position properly with respect to the vessel. Moreover, it is generally undesirable to expose the plugged material, e.g. collagen, to the blood stream where it may float down stream and risk causing an embolism. Another technique involves percutaneously suturing the puncture site. Percutaneous suturing devices, however, may require significant skills by the user and may be mechanical complex and expensive to manufacture.
Other closure devices include surgical fasteners. One known surgical fastener includes an annular base having legs that, in a relaxed state, extend in a direction substantially perpendicular to a plane defined by the base and slightly inwards toward one another. During use, the fastener is fit around the outside of a cannula, thereby deflecting the legs outward. The cannula is placed in an incision, and the fastener is slid along the cannula until the legs pierce into the blood vessel. When the cannula is withdrawn, the legs move towards one another and back to the relaxed state to close the incision. Staples can also be used to close a wound or incision. Staples, however, tend to have a large cross-sectional profile and therefore may not be easy to deliver through a percutaneous site to close an opening in a vessel wall.
Accordingly, improved methods and devices for closing a vascular puncture wound are needed.